title: Understanding macrographia in children with autism spectrum disorders.
abstract: It has been consistently reported that children with autism spectrum disorders (ASD) show considerable handwriting difficulties, specifically relating to accurate and consistent letter formation, and maintaining appropriate letter size. The aim of this study was to investigate the underlying factors that contribute to these difficulties, specifically relating to motor control. We examined the integrity of fundamental handwriting movements and contributions of neuromotor noise in 26 children with ASD aged 8-13 years (IQ>75), and 17 typically developing controls. Children wrote a series of four cursive letter l's using a graphics tablet and stylus. Children with ASD had significantly larger stroke height and width, more variable movement trajectory, and higher movement velocities. The absolute level of neuromotor noise in the velocity profiles, as measured by power spectral density analysis, was significantly higher in children with ASD; relatively higher neuromotor noise was found in bands >3 Hz. Our findings suggest that significant instability of fundamental handwriting movements, in combination with atypical biomechanical strategies, contribute to larger and less consistent handwriting in children with ASD.
authors.affiliation: School of Psychology and Psychiatry, Monash University, Wellington Road, Clayton, VIC, Australia. beth.johnson@monash.edu
authors.forename: Beth P
authors.initials: BP
authors.lastname: Johnson
authors.forename: James G
authors.initials: JG
authors.lastname: Phillips
authors.forename: Nicole
authors.initials: N
authors.lastname: Papadopoulos
authors.forename: Joanne
authors.initials: J
authors.lastname: Fielding
authors.forename: Bruce
authors.initials: B
authors.lastname: Tonge
authors.forename: Nicole J
authors.initials: NJ
authors.lastname: Rinehart
mesh_terms: D000293:Adolescent; D000381:Agraphia / Q000209:etiology* / Q000503:physiopathology; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000150:complications* / Q000503:physiopathology; D005260:Female; D006236:Handwriting; D006801:Humans; D008297:Male; D009048:Motor Skills; D019957:Motor Skills Disorders / Q000150:complications* / Q000503:physiopathology; D009068:Movement
keywords: Autism spectrum disorders; Fine motor; Handwriting; Manual dexterity